In semiconductor devices using nitride semiconductors such as LDs (Laser Diodes) LEDs (Light Emitting Diodes) and HEMT (High Electron Mobility Transistors), there is a demand for suppressing deterioration and breakage of a nitride semiconductor layer during processes from crystal growth to packaging.
For example, when the nitride semiconductor layer is grown on a silicon substrate, there are proposed various structures such as a structure in which composition is continuously inclined and a superlattice structure in which two layers with different compositions are alternately stacked. However, the conventional methods are insufficient in terms of suppression of deterioration and breakage of the nitride semiconductor layer, and thus the methods have room for improvement.